1. Field of the Invention
The present invention relates to a retaining device, and more particularly to a retaining device for a sensor of a revolution counter of a cycling vehicle.
2. Description of the Prior Art
Typical revolution counter which is commercially available in Taiwan, Republic of China is shown in FIGS. 5 and 6 and comprises a magnet 42 fixed on a spoke 41 of a wheel 40 of a cycling vehicle, such as a cycling exerciser, and a sensor 60 integrally fixed to a clamp ring 30 which is coupled to a frame fork 30 of the cycling vehicle by a bolt 63. The distance between the magnet 42 and the wheel axle 44 is equal to the distance between the sensor 60 and the wheel axle 44 so that the sensor 60 can count the revolutions of the wheel 40 by the relative movement between the magnet 42 and the sensor 60. However, the spokes 41 of the wheel 40 are slightly inclined relative to the frame fork 30, and the angular position of the sensor 60 can not be adjusted so that the magnet 42 and the sensor 60 can not be disposed in parallel precisely and so that a measurement error may be generated.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional retaining devices for sensors.